>>would in effect become some kind of binding to MFC (or whatever Windows uses now?)

Windows (32bit) always has and still uses win32, MFC is an abstraction on win32 to make programming easier, same for winforms. Wimp draws to windows using win32, there will probably be something like Wimp for MacOSX in the near future.
I donít know why people still bitch about GTK+ apps on windows, with Wimp I find they are sufficiently native. If thatís not sufficient for you, think about this, is it usual for all window apps to look the same?